A numerical relativity scheme for cosmological simulations

@article{Daverio2016ANR,
  title={A numerical relativity scheme for cosmological simulations},
  author={David Daverio and Yves Dirian and Ermis Mitsou},
  journal={arXiv: General Relativity and Quantum Cosmology},
  year={2016}
}
Cosmological simulations involving the fully covariant gravitational dynamics may prove relevant in understanding relativistic/non-linear features and, therefore, in taking better advantage of the upcoming large scale structure survey data. We propose a new 3+1 integration scheme for General Relativity in the case where the matter sector contains a minimally-coupled perfect fluid field. The original feature is that we completely eliminate the fluid components through the constraint equations… 

Figures from this paper

Comparing Fully General Relativistic and Newtonian Calculations of Structure Formation
In the standard approach to studying cosmological structure formation, the overall expansion of the Universe is assumed to be homogeneous, with the gravitational effect of inhomogeneities encoded
Cosmological backreaction in the presence of radiation and a cosmological constant
We construct high-precision models of the Universe that contain radiation, a cosmological constant, and periodically distributed inhomogeneous matter. The density contrasts in these models are
General relativistic cosmological N-body simulations. Part I. Time integration
This is the first in a series of papers devoted to fully general-relativistic $N$-body simulations applied to late-time cosmology. The purpose of this paper is to present the combination of a
Nonlinear approximation schemes in relativistic cosmology
In this thesis I present two main projects, based on the application of different nonlinear approximation schemes in relativistic cosmology. The first project comprises effects on the matter
Einstein-Vlasov calculations of structure formation
We study the dynamics of small inhomogeneities in an expanding universe collapsing to form bound structures using full solutions of the Einstein-Vlasov (N-body) equations. We compare these to
A cosmologically motivated reference formulation of numerical relativity
The application of numerical relativity to cosmological spacetimes is providing new insights into the behavior of Einstein's equations, beyond common approximations. In order for simulations to be
The background Friedmannian Hubble constant in relativistic inhomogeneous cosmology and the age of the Universe
In relativistic inhomogeneous cosmology, structure formation couples to average cosmological expansion. A conservative approach to modelling this assumes an Einstein--de Sitter model (EdS) at early
Replacing dark energy by silent virialisation
Standard cosmological $N$-body simulations have background scale factor evolution that is decoupled from non-linear structure formation. Prior to gravitational collapse, kinematical backreaction
Non-comoving baryons and cold dark matter in cosmic voids
We examine the fully relativistic evolution of cosmic voids constituted by baryons and cold dark matter (CDM), represented by two non-comoving dust sources in a $$\varLambda $$ΛCDM background. For
Ray tracing and Hubble diagrams in post-Newtonian cosmology
On small scales the observable Universe is highly inhomogeneous, with galaxies and clusters forming a complex web of voids and filaments. The optical properties of such configurations can be quite
...
1
2
...

References

SHOWING 1-10 OF 105 REFERENCES
General relativistic N -body simulations in the weak field limit
We develop a formalism for general relativistic $N$-body simulations in the weak field regime, suitable for cosmological applications. The problem is kept tractable by retaining the metric
Inhomogeneous cosmology with numerical relativity
We perform three-dimensional numerical relativity simulations of homogeneous and inhomogeneous expanding spacetimes, with a view towards quantifying non-linear effects from cosmological
N-body methods for relativistic cosmology
We present a framework for general relativistic N-body simulations in the regime of weak gravitational fields. In this approach, Einstein's equations are expanded in terms of metric perturbations
Newtonian and relativistic cosmologies
Cosmological N-body simulations are now being performed using Newtonian gravity on scales larger than the Hubble radius. It is well known that a uniformly expanding, homogeneous ball of dust in
Effects of Nonlinear Inhomogeneity on the Cosmic Expansion with Numerical Relativity.
TLDR
It is found that collapsing perturbations reach the turnaround point much earlier than expected from the reference spherical top-hat collapse model and that the local deviation of the expansion rate from the homogeneous one can be as high as 28% at an underdensity, for an initial density contrast of 10^{-2}.
gevolution: a cosmological N-body code based on General Relativity
We present a new N-body code, gevolution, for the evolution of large scale structure in the Universe. Our code is based on a weak field expansion of General Relativity and calculates all six metric
Concordance cosmology without dark energy
According to the separate universe conjecture, spherically symmetric sub-regions in an isotropic universe behave like mini-universes with their own cosmological parameters. This is an excellent
Relativistic Interpretation of Newtonian Simulations for Cosmic Structure Formation
The standard numerical tools for studying non-linear collapse of matter are Newtonian $N$-body simulations. Previous work has shown that these simulations are in accordance with General Relativity
An Exact quantification of backreaction in relativistic cosmology
An important open question in cosmology is the degree to which the Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) solutions of Einstein's equations are able to model the large-scale behavior of the
Towards a stable numerical evolution of strongly gravitating systems in general relativity: The conformal treatments
We study the stability of three-dimensional numerical evolutions of the Einstein equations, comparing the standard ADM formulation to variations on a family of formulations that separate out the
...
1
2
3
4
5
...